On Dec 23, 6:44*pm, John Hall wrote:
In article
,
*Scott W writes:

On 23 Dec, 07:51, Nick wrote:
There seems to be some suggestion (from Darren's latest model
interpretation) that the cold spell around Wednesday/Thursday next
week will only be temporary, with predictable January zonality setting
in after that. What are people's feelings on this? Are we now looking
at yet another of these winters which start promising, only to descend
into mildness once Christmas is over?

Oh well, at least the nights will be drawing out by then.

Nick

I was under the impression that the next cold plunge the first week of
January will be the real deal - and make this last cold spell look
like a tea party...

Judging by the GFS 12Z ensemble, it looks like it will be comparable in
intensity to this one.
--
John Hall *"[It was] so steep that at intervals the street broke into steps,
* * * * * * like a person breaking into giggles or hiccups, and then resumed
* * * * * * its sober climb, until it had another fit of steps."
* * * * * * * * * * * * * * * * * * * Ursula K Le Guin "The Beginning Place"

Judging by the 12z ECM, it may well not happen! It's a long way off
and just impossible to say with certainty that either of the views
expressed so far will achieve outcome. I can well understand why there
would be quite a difference of opinion. A colder spell may return, but
I can't see enough model agreement, of consistency to forecast that.
The same goes for a January establishment of zonal conditions. The
MetO's tea-break 6-15 day precis says this:

"The start of next week is likely to start unsettled with showers or
longer spells of rain, but also some dry and brighter interludes. Some
more persistent and heavy rain is expected to spread into southern and
central parts during Monday. This is likely to persist into Tuesday,
with a risk of snow on hills. Temperatures are expected to be below
average , especially in the north. The middle of next week will
continue unsettled with further showers or longer spells of rain, but
also some dry and brighter spells. It is likely to become colder, with
the showers turning increasing to snow, and some sharp overnight
frosts. The further outlook should continue much the same, but
indications are that it will become more settled and less perhaps
cold."

I know it's already out of date, but I think it sums up the present
difficulties. The MetO certainly don't go with a re-establishment of
cold at 10 days+, but exactly what they think the weather will be for
the period 10-16 days hence in that forecast isn't exactly clear. I
can't blame them. If I was pushed, from the last few sets of charts,
I'd go colder rather than milder, as I think there is more chance of
northern blocking establishing itself, than, say, a European high
becoming dominant, with a more northerly tracking jet, but, like I
said, there's nothing like enough agreement, or consistency, to have
reasonable confidence in any outcome at T240. There really have been
some lurches in model output forecasts over the last 3/4 days. We can
all read the charts, but to forecast with any accuracy at 10 days plus
is extraordinarily difficult.